Suppose there were an experience machine that would give you any experience you desired. Superduper neuropsychologists could stimulate your brain so that you would think and feel you were writing a great novel, or making a friend, or reading an interesting book. All the time you would be floating in a tank, with electrodes attached to your brain. Should you plug into this machine for life, preprogramming your life experiences?...Of course, while in the tank you won't know that you're there; you'll think that it's all actually happening...Would you plug in?
Robert Nozick (1974). “Anarchy, state, and utopia”